Technical data

4-14
Hardkey and Softkey Reference
control the laser.
LEFT LOWER. draws a quarter-page plot in the lower left quadrant of the page.
LEFT UPPER. draws a quarter-page plot in the upper left quadrant of the page.
LIGHTWAVE PARAMETERS. presents a menu that allows you to select a lightwave measurement: optical reflection,
optical transmission, electrical-to-optical transmission, and optical-to-electrical transmission.
LIGHTWAVE TESTS. leads to the internal service test for the lightwave portion of the hardware.
LIMIT LINE. selects the standard limit line choice. This selection leads to a series of menus used to define limits or
specifications with which to compare a test device. Refer to “Limit Line Operation” in the “Operating Concepts”
chapter of the user’s guide and the limit line testing section of the “Making Measurements” chapter of the user’s guide.
LIMIT LINE OFFSETS. leads to the offset limits menu, which is used to offset the complete limit set in either stimulus or
amplitude value.
LIMIT LINE on OFF. turns limit lines on or off. To define limits, use the EDIT LIMIT LINE softkey described below. If
limits have been defined and limit lines are turned on, the limit lines are displayed on the LCD for visual comparison of
the measured data in all Cartesian formats. If limit lines are on, they are plotted with the data on a plot, and saved in
memory with an instrument state. In a listing of values from the copy menu with limit lines on, the upper limit and
lower limit are listed together with the pass or fail margin, as long as other listed data allows sufficient space.
LIMIT MENU. accesses the menu that allows you to set up the three limit line types: standard limit lines, ripple limit
lines, and bandwidth limit lines.
LIMIT TEST on OFF. turns limit testing on or off. When limit testing is on, the data is compared with the defined limits at
each measured point. Limit tests occur at the end of each sweep, whenever the data is updated, when formatted data is
changed, and when limit testing is first turned on. Limit testing is available for both magnitude and phase values in
Cartesian formats. In polar and Smith chart formats, the value tested depends on the marker mode and is the
magnitude or the first value in a complex pair. The message "NO LIMIT LINES DISPLAYED" is displayed in polar and
Smith chart formats if limit lines are turned on. Five indications of pass or fail status are provided when limit testing is
on. A PASS or FAIL message is displayed at the right of the LCD. The trace vector leading to any measured point that is
out of limits is set to red at the end of every limit test, both on a displayed plot and a hard copy plot. The limit fail
beeper sounds if it is turned on. In a listing of values using the copy menu, an asterisk * is shown next to any measured
point that is out of limits. A bit is set in the GPIB status byte.
LIMIT TEST RESULT. puts the result of a limit test into the display title.
LIMIT TYPE. leads to the limit type menu, where one of three segment types can be selected: sloping line, flat line, or
single point.
LIN FREQ. activates a linear frequency sweep displayed on a standard graticule with ten equal horizontal divisions. This
is the default preset sweep type.
LIN MAG. displays the linear magnitude format. This is a Cartesian format used for unitless measurements such as
reflection coefficient magnitude ρ or transmission coefficient magnitude τ, and for linear measurement units. It is used
for display of conversion parameters and time domain transform data.
LIN MKR. displays a readout of the linear magnitude and the phase of the active marker. Marker magnitude values are
expressed in units and phase is expressed in degrees.
LINE/MATCH. provides access to the Line/Match Menu for TRL/LRM calibration.
LINE TYPE DATA. selects the line type for the data trace plot. The default line type is 7, which is a solid unbroken line.
LINE TYPE MEMORY. selects the line type for the memory trace plot. The default line type is 7.
LIST. provides a tabular listing of all the measured data points and their current values, together with limit information
if it is turned on. At the same time, the screen menu is presented, to enable hard copy listings and access new pages of
the table. 30 lines of data are listed on each page, and the number of pages is determined by the number of
measurement points specified in the stimulus menu.
LIST FREQ [STEPPED] or [SWEPT]. provides two user-definable arbitrary frequency list modes. This list is defined
and modified using the edit list menu and the edit subsweep menu. Up to 30 frequency subsweeps (called “segments”)
of several different types can be specified, for a maximum total of 1601 points. One list is common to both channels.
Once a frequency list has been defined and a measurement calibration performed on the full frequency list, one or all of
the frequency segments can be measured and displayed without loss of calibration. For more information on the
different list frequency sweep modes, refer to “Sweep Types” on page 5-6“.